1. Field of the Invention
The present invention relates to a method and system for automatically attaching works to main assemblies such as vehicle bodies which are continuously being carried on a conveyor.
2. Description of the Prior Art
In a vehicle's assembly line of a recent automotive manufacturing factory, such attaching operations for various works (windshields, combination lamps, seats, and so on) to vehicle bodies which are sequentially carried on, e.g., a slat conveyor moved at a predetermined speed, are carried out with an operator or operators at each operation stage of required works attaching a given work selected by reference to a production specification card prepared for each vehicle body. Each operator rises on a man conveyor moved in synchronization with the slat conveyor. However, recently there is a strong demand for such attachment operations of various works to vehicle bodies to be automated with an industrial robot in place of the operator.
To answer such a demand, it has been proposed that, e.g., a technique of factory automation (FA) over an entire assembly line which is recently being put into practice at various manufacturing factories be applied to such work attachment operations.
When the factory automation technique over the entire assembly line is applied, however, there are many problems in terms of technological difficulty and cost performance since it becomes necessary to construct a large scale and systematic factory automation line including highly intelligent robots to be newly developed.
In addition, since an enormous amount of costs is required to reconstruct installations and the automotive assembly factory is relatively large in scale as compared with other manufacture factories (e.g., manufacturing factories in electric appliances), it is desirable to maintain the existing installations except for a new installation of the factory. The above factory automation technique does not satisfy the above desired requirements.
Under such circumstances, a technique suitable for such automotive manufacturing factories has been demanded which satisfies the following five conditions:
(a) requiring little change in installations;
(b) capable of being readily put into practice in the current assembly line;
(c) utilizing recently developed robots without reconstruction;
(d) capable of utilizing a robot irrespectively of its kind; and
(e) being low in cost.